/**
* It should return stats.
*/
public function testStats()
{
$distribution = new Distribution([-50, 0, 50, 100]);
$this->assertEquals(100, $distribution->getSum());
$this->assertEquals(25, $distribution->getMean());
$this->assertEquals(-50, $distribution->getMin());
$this->assertEquals(100, $distribution->getMax());
$this->assertEquals(56, round($distribution->getStdev()));
$this->assertEquals(3125, $distribution->getVariance());
$this->assertEquals(25, round($distribution->getMode()));
}